Pennsylvania businesses better prepare for medical marijuana because they're going to have to deal with a whole range of complications once their employees start using it.

That was the consensus of the panelists who participated in a forum Thursday morning sponsored by the Greater Lehigh Valley Chamber of Commerce

Under the law, businesses will not be able to avoid the issue simply by firing employees who use medical marijuana, noted Frank Troilo, a lawyer who specializes in workers' compensation at Zenith Insurance Co.

State Health Secretary Karen Murphy announces the state Health Department is developing its first set of regulations for Pennsylvania’s new medical marijuana program.

State Health Secretary Karen Murphy announces the state Health Department is developing its first set of regulations for Pennsylvania’s new medical marijuana program.

"The real important thing about this," added Keya Denner, an employment lawyer at Norris, McLaughlin & Marcus, "is that it creates a new protected class among your workers."

Surrounded by a jubilant crowd of medical marijuana supporters at the Capitol building in Harrisburg, Gov. Tom Wolf signed the medical marijuana bill into law on a Sunday afternoon in mid-April. Upon taking full effect, the law will allow patients to take marijuana in pill, oil, vapor, ointment or liquid form. Smoking marijuana is not covered.

Eventually, the state will license up to 25 growers and processors, and as many as 50 dispensaries, which could each operate three locations, though generally not within 1,000 feet of a school or day care center.

Other aspects of Pennsylvania's medical marijuana program are under development. Temporary regulations are expected to be issued by the end of this ear for growers and processors; dispensaries and laboratories; physicians and research institutions; and patients and caregivers.

Thursday's forum at DeSales University in Center Valley was moderated by Chamber President Tony Iannelli, who asked if medical marijuana was a step toward the legalization of recreational use.

Tom Santanna, a Harrisburg lobbyist, sought to allay some of the fears among the roughly 100 people in the audience.

The law permits specially certified doctors to prescribe medical marijuana for 17 conditions, including pain. "It will not permit workers to go out to their cars and smoke a joint during lunch break," he said.

Denner made clear the new law raises complications for workplace policies such as drug testing and "zero tolerance" of drug use.

"How do you know if someone is impaired?" he asked. "I don't have the answer for that."

Troilo suggested employers monitor any employee using medical marijuana "to make sure the employee is not doing any type of work that would put them at risk."

Another point of concern raised by the panel's lawyers was liability, particularly when employees who use medical marijuana cross state lines, since marijuana use remains illegal under federal law.

In conclusion, some of the panelists agreed that businesses should update their workplace policies and job descriptions in advance of medical marijuana. Clear ground rules will help employers and employees minimize conflict and controversy, they said.